FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2017

Schedule of cash equivalents, restricted cash and marketable securities by security type

Cash equivalents, restricted cash and marketable securities by security type at March 31, 2017 were as follows:

			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
(In thousands)	Cost		Gains		Losses			Fair Value
Included in cash and cash equivalents:
Money market funds	$	9,946	$	—	$	—		$	9,946
Corporate notes	2,862		—		—			2,862

	$	12,808	$	—	$	—		$	12,808

Restricted cash:
Certificate of deposit	$	268	$	—	$	—		$	268

Marketable securities:
Government-sponsored enterprise securities (due in less than one year)	$	7,500	$	—	$	(9	)	$	7,491
Government-sponsored enterprise securities (due in one to two years)	10,000		—		(29		)	9,971
Commercial paper (due in less than one year)	20,577		21		(3		)	20,595
Corporate notes (due in less than one year)	56,382		1		(37		)	56,346
Corporate notes (due in one to two years)	12,170		—		(15		)	12,155

	$	106,629	$	22	$	(93	)	$	106,558

Cash equivalents, restricted cash and marketable securities by security type at December 31, 2016 were as follows:

	Amortized		Gross Unrealized		Gross Unrealized			Estimated
(In thousands)	Cost		Gains		Losses			Fair Value
Included in cash and cash equivalents:
Money market funds	$	11,193	$	—	$	—		$	11,193

Restricted cash:
Certificate of deposit	$	268	$	—	$	—		$	268

Marketable securities:
Government-sponsored enterprise securities (due in less than one year)	$	5,000	$	—	$	(3	)	$	4,997
Government-sponsored enterprise securities (due in one to two years)	12,500		—		(42		)	12,458
Commercial paper (due in less than one year)	31,024		50		(5		)	31,069
Corporate notes (due in less than one year)	66,012		4		(47		)	65,969
Corporate notes (due in one to two years)	1,506		—		(10		)	1,496

	$	116,042	$	54	$	(107	)	$	115,989

Schedule of marketable securities with unrealized losses

	Less Than 12 Months					12 Months or Greater					Total
	Estimated		Gross Unrealized			Estimated		Gross Unrealized			Estimated		Gross Unrealized
(In thousands)	Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
As of March 31, 2017:
Government-sponsored enterprise securities (due in less than one year)	$	7,491	$	(9	)	$	—	$	—		$	7,491	$	(9	)
Government-sponsored enterprise securities (due in one to two years)	9,971		(29		)	—		—			9,971		(29		)
Commercial paper (due in less than one year)	5,885		(3		)	—		—			5,885		(3		)
Corporate notes (due in less than one year)	46,236		(34		)	5,916		(3		)	52,152		(37		)
Corporate notes (due in one to two years)	12,155		(15		)	—		—			12,155		(15		)

	$	81,738	$	(90	)	$	5,916	$	(3	)	$	87,654	$	(93	)

As of December 31, 2016:
Government-sponsored enterprise securities (due in less than one year)	$	4,997	$	(3	)	$	—	$	—		$	4,997	$	(3	)
Government-sponsored enterprise securities (due in one to two years)	12,458		(42		)	—		—			12,458		(42		)
Commercial paper (due in less than one year)	8,365		(5		)	—		—			8,365		(5		)
Corporate notes (due in less than one year)	39,218		(37		)	6,944		(10		)	46,162		(47		)
Corporate notes (due in one to two years)	1,496		(10		)	—		—			1,496		(10		)

	$	66,534	$	(97	)	$	6,944	$	(10	)	$	73,478	$	(107	)

Schedule of financial instruments measured at fair value on recurring basis

The following table presents information about our financial instruments that are measured at fair value on a recurring basis as of March 31, 2017 and indicates the fair value category assigned.

	Fair Value Measurements at Reporting Date Using
	Quoted Prices in Active Markets for		Significant Other		Significant Unobservable
	Identical Assets		Observable Inputs		Inputs
(In thousands)	Level 1		Level 2		Level 3		Total
Assets
Money market funds(1)	$	9,946	$	—	$	—	$	9,946
Government-sponsored enterprise securities(2)(3)	—		17,462		—		17,462
Commercial paper(2)	—		20,595		—		20,595
Corporate notes(1)(2)(3)	—		71,363		—		71,363

Total	$	9,946	$	109,420	$	—	$	119,366

The following table presents information about our financial instruments that are measured at fair value on a recurring basis as of December 31, 2016 and indicates the fair value category assigned.

	Fair Value Measurements at Reporting Date Using
	Quoted Prices in Active Markets for		Significant Other		Significant Unobservable
	Identical Assets		Observable Inputs		Inputs
(In thousands)	Level 1		Level 2		Level 3		Total
Assets
Money market funds(1)	$	11,193	$	—	$	—	$	11,193
Government-sponsored enterprise securities(2)(3)	—		17,455		—		17,455
Commercial paper(2)	—		31,069		—		31,069
Corporate notes(2)(3)	—		67,465		—		67,465

Total	$	11,193	$	115,989	$	—	$	127,182

(1)

Included in cash and cash equivalents on our condensed balance sheets.

(2)

Included in current portion of marketable securities on our condensed balance sheets.

(3)

Included in noncurrent portion of marketable securities on our condensed balance sheets.